Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neurons listen to glia cells

15.12.2014

Communication in the brain: research collaboration uncovers a novel mechanism of altered information processing between neurons / Responsible is a distinct class of glial cells / Major relevance for learning and processing of sensory input / Publication in the prestigious journal PLoS Biology

Scientists at Johannes Gutenberg University Mainz (JGU) in Germany have discovered a new signal pathway in the brain that plays an important role in learning and the processing of sensory input. It was already known that distinct glial cells receive information from neurons. However, it was unknown that these same glial cells also transmit information to neurons.


Oligodendrocyte progenitor cells in the brain (OPC, green) influence synaptic signaling between neurones (red) integrated in the neuronal network.

source: Institute of Molecular Cell Biology, JGU


Model of the molecular signaling pathways between OPC (green), a subgroup of glial cells, and the neuronal network (grey). The release of a fragment of the glial NG2 protein by enhanced protease activity in the OPC is a central component (see 1), modulating the signal transduction at defined (excitatory) synapses of the neuronal network (see 2).

source: Institute of Molecular Cell Biology, JGU

The glia release a specific protein fragment that influences neuronal cross-talk, most likely by binding to the synaptic contacts that neurons use for communication. Disruption of this information flow from the glia results in changes in the neural network, for example during learning processes.

The team composed of Dr. Dominik Sakry, Dr. Angela Neitz, Professor Jacqueline Trotter, and Professor Thomas Mittmann unravelled the underlying mechanism, from the molecular and cellular level to the network and finally the resulting behavioral consequences. Their findings constitute major progress in understanding complex pathways of signal transmission in the brain.

In mammalian brains glial cells outnumber nerve cells, but their functions are still largely unelucidated. A group of glial cells, so-called oligodendrocyte precursor cells (OPC), develop into the oligodendrocytes which ensheathe neuronal axons with a protective myelin layer thus promoting the rapid transmission of signals along the axon. Interestingly, these OPCs are present as a stable proportion – some five to eight percent of all cells in all brain regions, including adult brains. The Mainz-based researchers decided to take a closer look at these OPCs.

In 2000 it was discovered that OPCs receive signals from the neural network via synaptic contacts that they make with neurons. "We have now discovered that the precursor cells do not only receive information via the synapses, but in their turn use these to transmit signals to adjacent nerve cells. They are thus an essential component of the network," explained Professor Jacqueline Trotter from the Institute of Molecular Cell Biology at Mainz University.

Classically, neurons have been considered as the major players in the brain. Over the past few years, however, increasing evidence has come to light that glial cells may play an equally important role. "Glial cells are enormously important for our brains and we have now elucidated in detail a novel important role for glia in signal transmission," explained Professor Thomas Mittmann of the JGU Institute of Physiology.

The chain of communication starts with signals traveling from the neurons to the OPCs across the synaptic cleft via the neurotransmitter glutamate. This results in a stimulation of the activity of a specific protease, the alpha-secretase ADAM 10 in OPCs, which acts on the NG2 protein expressed by the precursor cells releasing a NG2 fragment into the extracellular space, where it influences neighboring neuronal synapses. The neurons react to this in the form of altered electrical activity. "We can use patch-clamp techniques to hear, as it were, how the cells talk to one another," said Thomas Mittmann.

"The process starts with the reception of signals coming from the neurons by the OPCs. This means that the feedback to the neurons cannot be seen as separated from the signal reception," explained Dominik Sakry, joint first author of the study, describing the cascade of events. The role of NG2 in this process became apparent when the researchers removed the protein: neuronal synaptic function is altered, modifying learning and disrupting the processing of sensory input that manifests in the form of behavioral changes in test animals.

The evidence that the communication between the two cell types in the brain is not a one-way system but a complex mechanism involving feedback loops was obtained in a collaborative project involving physiologists and molecular biologists. Participating in the project at Mainz University were the Faculties of Biology and Medicine and the Focus Program Translational Neurosciences (FTN) in the form of platform technology provided by the Mouse Behavioral Unit (MBU). The project was additionally supported by two Mainz Collaborative Research Centers (CRC 1080 and CRC-TR 128) and involved participation of the Leibniz Institute for Neurobiology in Magdeburg. Scientists from seven countries participated in the study.

The evidence that the communication between the two cell types in the brain is not a one-way system but a complex mechanism involving feedback loops was obtained within a broad-based project in which both physiologists and molecular biologists collaborated. Participating in the project at Mainz University were the Faculties of Medicine and Biology, the Focus Program Translational Neurosciences (FTN) and its Mouse Behavior Unit (MBU) together with two Mainz Collaborative Research Centers (CRC 1080 and CRC-TR 128) and the Leibniz Institute for Neurobiology in Magdeburg. Scientists from seven countries took part in the study.

Publication:
Dominik Sakry, Angela Neitz et al.
Oligodendrocyte Precursor Cells Modulate the Neuronal Network by Activity-Dependent Ectodomain Cleavage of Glial NG2
PLoS Biology 12(11): e1001993, 11 November 2014
DOI: 10.1371/journal.pbio.1001993

Further information:
Professor Dr. Jacqueline Trotter
Institute of Molecular Cell Biology
Faculty 10: Biology
Johannes Gutenberg University Mainz (JGU)
D 55099 Mainz, GERMANY
phone +49 6131 39-20263 oder 39-22879
fax +49 6131 39-23840
e-mail: trotter@uni-mainz.de
http://www.blogs.uni-mainz.de/fb10molcellbio/

Professor Dr. Thomas Mittmann
Institute of Physiology
Mainz University Medical Center
D 55099 Mainz
phone +49 0613139-27261
fax +49 6131 39-25560
e-mail: mittmann@uni-mainz.de
http://www.physiologie.uni-mainz.de/

Related links:
http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001993 (Article)
http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001990 (Synopsis)
http://www.uni-mainz.de/presse/16582_ENG_HTML.php (Press release "Scientists at Mainz University decode mechanisms of cell orientation in the brain", 31 July 2013)

Weitere Informationen:

http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001993 - Article ;
http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001990 - Synopsis ;
http://www.uni-mainz.de/presse/16582_ENG_HTML.php - press release "Scientists at Mainz University decode mechanisms of cell orientation in the brain", 31 July 2013

Petra Giegerich | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

A new dead zone in the Indian Ocean could impact future marine nutrient balance

06.12.2016 | Earth Sciences

Significantly more productivity in USP lasers

06.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>